The present invention relates to a technique of making a production plan for a product in response to demand forecast and a production order for the product while considering production capacity on the manufacture side.
Production planning for a product is made in consideration of the production capacity on the manufacture side with respect to a production order presented by the sales side. If the production capacity of processes to be used is insufficient, the production planning is made by increasing the production capacity or adjusting the manufacture load (see Japanese Patent Laid-Open Publication No. 2001-184 (hereinafter referred to as Patent Document 1) and Japanese Patent Laid-Open Publication No. 2000-194755 (hereinafter referred to as Patent Document 2)).
In Patent Document 1, a period where the manufacture load exceeds the equipment capacity is extracted, and the equipment capacity is increased and work leveling of the manufacture load is performed based on a given adjustment rule.
Patent Document 1 describes a method of increasing workers or shortening the operation cycle when the work load exceeds the equipment capacity. The adjustment however is difficult in a case where workers cannot be supplied or transferred from another workplace. In a production mode, such as product assembly, whose bottleneck is manpower capacity, not equipment, training and an education period for new work are needed, so that workers cannot be easily transferred. It is therefore necessary to consider that the manpower capacity at a workplace is fixed in a certain period, after which workers are flexibly accommodated between workplaces. The accommodation of workers between workplaces means that, for example, increasing the capacity of a workplace A by 10 points means reduction of the capacitance of a workplace B by 10 points. In Patent Document 1, since only equipment is targeted, the mutual effect of reducing the capacity of one item of equipment according to an increase in the capacity of another item of equipment is not considered.
With regard to the manpower capacity, in particular, the manpower is procured and optimized in previous production planning, and is not optimized in response to the latest production order. If the manpower capacity is fixedly set in every period, therefore, there occurs an event in which workers are insufficient at one workplace while there are excess workers at another workplace, resulting in the possibility that a production plan is made for lower than the original capacity.
In Patent Document 2, while optimal assignment of persons is ordered for production planning, giving consideration to the state of worker operation-skill acquisition when deciding the worker assignment for cell production or the like, a training period for workers to learn work skills for another workplace is not considered.